In a previous commit 69403bad97aa, sta->sdata can be NULL, and thus it
should be checked before being used.
However, in the same call stack, sta->sdata is also used in the
following functions:
ieee80211_ba_session_work()
___ieee80211_stop_rx_ba_session(sta)
ht_dbg(sta->sdata, ...); -> No check
sdata_info(sta->sdata, ...); -> No check
ieee80211_send_delba(sta->sdata, ...) -> No check
___ieee80211_start_rx_ba_session(sta)
ht_dbg(sta->sdata, ...); -> No check
ht_dbg_ratelimited(sta->sdata, ...); -> No check
ieee80211_tx_ba_session_handle_start(sta)
sdata = sta->sdata; if (!sdata) -> Add check by previous commit
___ieee80211_stop_tx_ba_session(sdata)
ht_dbg(sta->sdata, ...); -> No check
ieee80211_start_tx_ba_cb(sdata)
sdata = sta->sdata; local = sdata->local -> No check
ieee80211_stop_tx_ba_cb(sdata)
ht_dbg(sta->sdata, ...); -> No check
Thus, to avoid possible null-pointer dereferences, the related checks
should be added.
These results are reported by a static tool designed by myself.
Signed-off-by: Jia-Ju Bai <[email protected]>
---
net/mac80211/agg-rx.c | 68 ++++++++++++++++++++++++++-----------------
net/mac80211/agg-tx.c | 16 ++++++++--
2 files changed, 55 insertions(+), 29 deletions(-)
diff --git a/net/mac80211/agg-rx.c b/net/mac80211/agg-rx.c
index c6fa53230450..6616970785a2 100644
--- a/net/mac80211/agg-rx.c
+++ b/net/mac80211/agg-rx.c
@@ -80,19 +80,21 @@ void ___ieee80211_stop_rx_ba_session(struct sta_info *sta, u16 tid,
RCU_INIT_POINTER(sta->ampdu_mlme.tid_rx[tid], NULL);
__clear_bit(tid, sta->ampdu_mlme.agg_session_valid);
- ht_dbg(sta->sdata,
- "Rx BA session stop requested for %pM tid %u %s reason: %d\n",
- sta->sta.addr, tid,
- initiator == WLAN_BACK_RECIPIENT ? "recipient" : "initiator",
- (int)reason);
+ if (sta->sdata) {
+ ht_dbg(sta->sdata,
+ "Rx BA session stop requested for %pM tid %u %s reason: %d\n",
+ sta->sta.addr, tid,
+ initiator == WLAN_BACK_RECIPIENT ? "recipient" : "initiator",
+ (int)reason);
+ }
- if (drv_ampdu_action(local, sta->sdata, ¶ms))
+ if (sta->sdata && drv_ampdu_action(local, sta->sdata, ¶ms))
sdata_info(sta->sdata,
"HW problem - can not stop rx aggregation for %pM tid %d\n",
sta->sta.addr, tid);
/* check if this is a self generated aggregation halt */
- if (initiator == WLAN_BACK_RECIPIENT && tx)
+ if (initiator == WLAN_BACK_RECIPIENT && tx && sta->sdata)
ieee80211_send_delba(sta->sdata, sta->sta.addr,
tid, WLAN_BACK_RECIPIENT, reason);
@@ -279,17 +281,21 @@ void ___ieee80211_start_rx_ba_session(struct sta_info *sta,
if (!sta->sta.deflink.ht_cap.ht_supported &&
!sta->sta.deflink.he_cap.has_he) {
- ht_dbg(sta->sdata,
- "STA %pM erroneously requests BA session on tid %d w/o HT\n",
- sta->sta.addr, tid);
+ if (sta->sdata) {
+ ht_dbg(sta->sdata,
+ "STA %pM erroneously requests BA session on tid %d w/o HT\n",
+ sta->sta.addr, tid);
+ }
/* send a response anyway, it's an error case if we get here */
goto end;
}
if (test_sta_flag(sta, WLAN_STA_BLOCK_BA)) {
- ht_dbg(sta->sdata,
- "Suspend in progress - Denying ADDBA request (%pM tid %d)\n",
- sta->sta.addr, tid);
+ if (sta->sdata) {
+ ht_dbg(sta->sdata,
+ "Suspend in progress - Denying ADDBA request (%pM tid %d)\n",
+ sta->sta.addr, tid);
+ }
goto end;
}
@@ -322,8 +328,10 @@ void ___ieee80211_start_rx_ba_session(struct sta_info *sta,
buf_size = sta->sta.max_rx_aggregation_subframes;
params.buf_size = buf_size;
- ht_dbg(sta->sdata, "AddBA Req buf_size=%d for %pM\n",
- buf_size, sta->sta.addr);
+ if (sta->sdata) {
+ ht_dbg(sta->sdata, "AddBA Req buf_size=%d for %pM\n",
+ buf_size, sta->sta.addr);
+ }
/* examine state machine */
lockdep_assert_held(&sta->ampdu_mlme.mtx);
@@ -332,9 +340,11 @@ void ___ieee80211_start_rx_ba_session(struct sta_info *sta,
if (sta->ampdu_mlme.tid_rx_token[tid] == dialog_token) {
struct tid_ampdu_rx *tid_rx;
- ht_dbg_ratelimited(sta->sdata,
- "updated AddBA Req from %pM on tid %u\n",
- sta->sta.addr, tid);
+ if (sta->sdata) {
+ ht_dbg_ratelimited(sta->sdata,
+ "updated AddBA Req from %pM on tid %u\n",
+ sta->sta.addr, tid);
+ }
/* We have no API to update the timeout value in the
* driver so reject the timeout update if the timeout
* changed. If it did not change, i.e., no real update,
@@ -350,9 +360,11 @@ void ___ieee80211_start_rx_ba_session(struct sta_info *sta,
goto end;
}
- ht_dbg_ratelimited(sta->sdata,
- "unexpected AddBA Req from %pM on tid %u\n",
- sta->sta.addr, tid);
+ if (sta->sdata) {
+ ht_dbg_ratelimited(sta->sdata,
+ "unexpected AddBA Req from %pM on tid %u\n",
+ sta->sta.addr, tid);
+ }
/* delete existing Rx BA session on the same tid */
___ieee80211_stop_rx_ba_session(sta, tid, WLAN_BACK_RECIPIENT,
@@ -362,9 +374,11 @@ void ___ieee80211_start_rx_ba_session(struct sta_info *sta,
if (ieee80211_hw_check(&local->hw, SUPPORTS_REORDERING_BUFFER)) {
ret = drv_ampdu_action(local, sta->sdata, ¶ms);
- ht_dbg(sta->sdata,
- "Rx A-MPDU request on %pM tid %d result %d\n",
- sta->sta.addr, tid, ret);
+ if (sta->sdata) {
+ ht_dbg(sta->sdata,
+ "Rx A-MPDU request on %pM tid %d result %d\n",
+ sta->sta.addr, tid, ret);
+ }
if (!ret)
status = WLAN_STATUS_SUCCESS;
goto end;
@@ -401,8 +415,10 @@ void ___ieee80211_start_rx_ba_session(struct sta_info *sta,
__skb_queue_head_init(&tid_agg_rx->reorder_buf[i]);
ret = drv_ampdu_action(local, sta->sdata, ¶ms);
- ht_dbg(sta->sdata, "Rx A-MPDU request on %pM tid %d result %d\n",
- sta->sta.addr, tid, ret);
+ if (sta->sdata) {
+ ht_dbg(sta->sdata, "Rx A-MPDU request on %pM tid %d result %d\n",
+ sta->sta.addr, tid, ret);
+ }
if (ret) {
kfree(tid_agg_rx->reorder_buf);
kfree(tid_agg_rx->reorder_time);
diff --git a/net/mac80211/agg-tx.c b/net/mac80211/agg-tx.c
index f9514bacbd4a..03b31b6e7ac7 100644
--- a/net/mac80211/agg-tx.c
+++ b/net/mac80211/agg-tx.c
@@ -368,8 +368,10 @@ int ___ieee80211_stop_tx_ba_session(struct sta_info *sta, u16 tid,
spin_unlock_bh(&sta->lock);
- ht_dbg(sta->sdata, "Tx BA session stop requested for %pM tid %u\n",
- sta->sta.addr, tid);
+ if (sta->sdata) {
+ ht_dbg(sta->sdata, "Tx BA session stop requested for %pM tid %u\n",
+ sta->sta.addr, tid);
+ }
del_timer_sync(&tid_tx->addba_resp_timer);
del_timer_sync(&tid_tx->session_timer);
@@ -776,7 +778,12 @@ void ieee80211_start_tx_ba_cb(struct sta_info *sta, int tid,
struct tid_ampdu_tx *tid_tx)
{
struct ieee80211_sub_if_data *sdata = sta->sdata;
- struct ieee80211_local *local = sdata->local;
+ struct ieee80211_local *local;
+
+ if (!sdata)
+ return;
+
+ local = sdata->local;
if (WARN_ON(test_and_set_bit(HT_AGG_STATE_DRV_READY, &tid_tx->state)))
return;
@@ -902,6 +909,9 @@ void ieee80211_stop_tx_ba_cb(struct sta_info *sta, int tid,
bool send_delba = false;
bool start_txq = false;
+ if (!sdata)
+ return;
+
ht_dbg(sdata, "Stopping Tx BA session for %pM tid %d\n",
sta->sta.addr, tid);
--
2.34.1
On Mon, Mar 20, 2023 at 09:35:33PM +0800, Jia-Ju Bai wrote:
> In a previous commit 69403bad97aa, sta->sdata can be NULL, and thus it
> should be checked before being used.
Please run checkpatch on this patch, and correct the commit description
style.
./scripts/checkpatch.pl -g HEAD
ERROR: Please use git commit description style 'commit <12+ chars of sha1> ("<title line>")' - ie: 'commit 69403bad97aa ("wifi: mac80211: sdata can be NULL during AMPDU start")'
#6:
In a previous commit 69403bad97aa, sta->sdata can be NULL, and thus it
>
> However, in the same call stack, sta->sdata is also used in the
> following functions:
>
> ieee80211_ba_session_work()
> ___ieee80211_stop_rx_ba_session(sta)
> ht_dbg(sta->sdata, ...); -> No check
> sdata_info(sta->sdata, ...); -> No check
> ieee80211_send_delba(sta->sdata, ...) -> No check
> ___ieee80211_start_rx_ba_session(sta)
> ht_dbg(sta->sdata, ...); -> No check
> ht_dbg_ratelimited(sta->sdata, ...); -> No check
> ieee80211_tx_ba_session_handle_start(sta)
> sdata = sta->sdata; if (!sdata) -> Add check by previous commit
> ___ieee80211_stop_tx_ba_session(sdata)
> ht_dbg(sta->sdata, ...); -> No check
> ieee80211_start_tx_ba_cb(sdata)
> sdata = sta->sdata; local = sdata->local -> No check
> ieee80211_stop_tx_ba_cb(sdata)
> ht_dbg(sta->sdata, ...); -> No check
I wonder if it would be better to teach ht_* do do nothing
if the first argument is NULL.
Also, are these theoretical bugs?
Or something that has been observed?
And has a reproducer?
> Thus, to avoid possible null-pointer dereferences, the related checks
> should be added.
>
> These results are reported by a static tool designed by myself.
>
> Signed-off-by: Jia-Ju Bai <[email protected]>
> Reported-by: TOTE Robot <[email protected]>
I see 4 copies of this patch in a few minutes.
As per the FAQ [1], please leave at least 24h between posts of a patch.
[1] https://www.kernel.org/doc/html/latest/process/maintainer-netdev.html
Hello Simon,
Thanks for the reply!
On 2023/3/21 0:49, Simon Horman wrote:
> On Mon, Mar 20, 2023 at 09:35:33PM +0800, Jia-Ju Bai wrote:
>> In a previous commit 69403bad97aa, sta->sdata can be NULL, and thus it
>> should be checked before being used.
> Please run checkpatch on this patch, and correct the commit description
> style.
>
> ./scripts/checkpatch.pl -g HEAD
> ERROR: Please use git commit description style 'commit <12+ chars of sha1> ("<title line>")' - ie: 'commit 69403bad97aa ("wifi: mac80211: sdata can be NULL during AMPDU start")'
> #6:
> In a previous commit 69403bad97aa, sta->sdata can be NULL, and thus it
Okay, I will revise it and run checkpatch.
>
>> However, in the same call stack, sta->sdata is also used in the
>> following functions:
>>
>> ieee80211_ba_session_work()
>> ___ieee80211_stop_rx_ba_session(sta)
>> ht_dbg(sta->sdata, ...); -> No check
>> sdata_info(sta->sdata, ...); -> No check
>> ieee80211_send_delba(sta->sdata, ...) -> No check
>> ___ieee80211_start_rx_ba_session(sta)
>> ht_dbg(sta->sdata, ...); -> No check
>> ht_dbg_ratelimited(sta->sdata, ...); -> No check
>> ieee80211_tx_ba_session_handle_start(sta)
>> sdata = sta->sdata; if (!sdata) -> Add check by previous commit
>> ___ieee80211_stop_tx_ba_session(sdata)
>> ht_dbg(sta->sdata, ...); -> No check
>> ieee80211_start_tx_ba_cb(sdata)
>> sdata = sta->sdata; local = sdata->local -> No check
>> ieee80211_stop_tx_ba_cb(sdata)
>> ht_dbg(sta->sdata, ...); -> No check
> I wonder if it would be better to teach ht_* do do nothing
> if the first argument is NULL.
Okay, I will use this way in patch v2.
>
> Also, are these theoretical bugs?
> Or something that has been observed?
> And has a reproducer?
These bugs are found by my static analysis tool, by extending a known
bug fixed in a previous commit 69403bad97aa.
Thus, they could be theoretical bugs.
>
>> Thus, to avoid possible null-pointer dereferences, the related checks
>> should be added.
>>
>> These results are reported by a static tool designed by myself.
>>
>> Signed-off-by: Jia-Ju Bai <[email protected]>
>> Reported-by: TOTE Robot <[email protected]>
> I see 4 copies of this patch in a few minutes.
> As per the FAQ [1], please leave at least 24h between posts of a patch.
>
> [1] https://www.kernel.org/doc/html/latest/process/maintainer-netdev.html
I am quite sorry for this, because my script of git send email was buggy.
I noticed this problem after sending the e-mail, and now I have fixed it :)
Best wishes,
Jia-Ju Bai
On Tue, Mar 21, 2023 at 03:40:40PM +0800, Jia-Ju Bai wrote:
> Hello Simon,
>
> Thanks for the reply!
>
>
> On 2023/3/21 0:49, Simon Horman wrote:
> > On Mon, Mar 20, 2023 at 09:35:33PM +0800, Jia-Ju Bai wrote:
> > > In a previous commit 69403bad97aa, sta->sdata can be NULL, and thus it
> > > should be checked before being used.
> > Please run checkpatch on this patch, and correct the commit description
> > style.
> >
> > ./scripts/checkpatch.pl -g HEAD
> > ERROR: Please use git commit description style 'commit <12+ chars of sha1> ("<title line>")' - ie: 'commit 69403bad97aa ("wifi: mac80211: sdata can be NULL during AMPDU start")'
> > #6:
> > In a previous commit 69403bad97aa, sta->sdata can be NULL, and thus it
>
> Okay, I will revise it and run checkpatch.
Thanks.
> > > However, in the same call stack, sta->sdata is also used in the
> > > following functions:
> > >
> > > ieee80211_ba_session_work()
> > > ___ieee80211_stop_rx_ba_session(sta)
> > > ht_dbg(sta->sdata, ...); -> No check
> > > sdata_info(sta->sdata, ...); -> No check
> > > ieee80211_send_delba(sta->sdata, ...) -> No check
> > > ___ieee80211_start_rx_ba_session(sta)
> > > ht_dbg(sta->sdata, ...); -> No check
> > > ht_dbg_ratelimited(sta->sdata, ...); -> No check
> > > ieee80211_tx_ba_session_handle_start(sta)
> > > sdata = sta->sdata; if (!sdata) -> Add check by previous commit
> > > ___ieee80211_stop_tx_ba_session(sdata)
> > > ht_dbg(sta->sdata, ...); -> No check
> > > ieee80211_start_tx_ba_cb(sdata)
> > > sdata = sta->sdata; local = sdata->local -> No check
> > > ieee80211_stop_tx_ba_cb(sdata)
> > > ht_dbg(sta->sdata, ...); -> No check
> > I wonder if it would be better to teach ht_* do do nothing
> > if the first argument is NULL.
>
> Okay, I will use this way in patch v2.
Maybe it is not a good idea.
But I think it is worth trying, at least locally, to see how it goes.
> > Also, are these theoretical bugs?
> > Or something that has been observed?
> > And has a reproducer?
>
> These bugs are found by my static analysis tool, by extending a known bug
> fixed in a previous commit 69403bad97aa.
> Thus, they could be theoretical bugs.
Thanks, understood.
I think it would be worth making that a bit clearer in the
patch description (commit message).
> > > Thus, to avoid possible null-pointer dereferences, the related checks
> > > should be added.
> > >
> > > These results are reported by a static tool designed by myself.
> > >
> > > Signed-off-by: Jia-Ju Bai <[email protected]>
> > > Reported-by: TOTE Robot <[email protected]>
> > I see 4 copies of this patch in a few minutes.
> > As per the FAQ [1], please leave at least 24h between posts of a patch.
> >
> > [1] https://www.kernel.org/doc/html/latest/process/maintainer-netdev.html
>
> I am quite sorry for this, because my script of git send email was buggy.
> I noticed this problem after sending the e-mail, and now I have fixed it :)
Thanks, I realised after I sent my previous email that something like that
might have happened. Thanks for fixing it.
On 2023/3/21 16:36, Simon Horman wrote:
>>>> However, in the same call stack, sta->sdata is also used in the
>>>> following functions:
>>>>
>>>> ieee80211_ba_session_work()
>>>> ___ieee80211_stop_rx_ba_session(sta)
>>>> ht_dbg(sta->sdata, ...); -> No check
>>>> sdata_info(sta->sdata, ...); -> No check
>>>> ieee80211_send_delba(sta->sdata, ...) -> No check
>>>> ___ieee80211_start_rx_ba_session(sta)
>>>> ht_dbg(sta->sdata, ...); -> No check
>>>> ht_dbg_ratelimited(sta->sdata, ...); -> No check
>>>> ieee80211_tx_ba_session_handle_start(sta)
>>>> sdata = sta->sdata; if (!sdata) -> Add check by previous commit
>>>> ___ieee80211_stop_tx_ba_session(sdata)
>>>> ht_dbg(sta->sdata, ...); -> No check
>>>> ieee80211_start_tx_ba_cb(sdata)
>>>> sdata = sta->sdata; local = sdata->local -> No check
>>>> ieee80211_stop_tx_ba_cb(sdata)
>>>> ht_dbg(sta->sdata, ...); -> No check
>>> I wonder if it would be better to teach ht_* do do nothing
>>> if the first argument is NULL.
>> Okay, I will use this way in patch v2.
> Maybe it is not a good idea.
> But I think it is worth trying, at least locally, to see how it goes.
After checking the code, I find that ht_* is actually a macro from _sdata_*.
Many code points use ht_* and _sdata_*, and thus I am not sure it is
fine to try this way.
For simplification, I still think checking sdata before the calls to
ht_* or _sdata_* should be more proper :)
>
>>> Also, are these theoretical bugs?
>>> Or something that has been observed?
>>> And has a reproducer?
>> These bugs are found by my static analysis tool, by extending a known bug
>> fixed in a previous commit 69403bad97aa.
>> Thus, they could be theoretical bugs.
> Thanks, understood.
> I think it would be worth making that a bit clearer in the
> patch description (commit message).
Okay.
I have sent the v2 patch, please have a look.
Thanks a lot :)
Best wishes,
Jia-Ju Bai